Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully covered. The description adds that the result is a single aggregated briefing across four categories, which is useful, but since an output schema exists it needn't detail return values and adds nothing on cost, freshness, or caching for what is presumably an expensive aggregation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, zero waste. The trigger condition is front-loaded and the content enumeration follows, so the agent gets the 'when' before the 'what'.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a parameterless, read-only tool with a rich output schema and full annotations, the description supplies the trigger and the scope needed to call it correctly. The one material omission is disambiguation from the other briefing/digest siblings, which would be needed to route reliably in this large toolset.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so there is no parameter semantics to explain; the baseline of 4 applies. The description correctly implies the briefing is unfiltered and scoped to the calling user, with no arguments required.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource (get one daily briefing) and enumerates its contents: birthdays, fading relationships, open tasks, reminders. That clearly distinguishes it from generic list tools, but it never accounts for the very similar siblings agent.routine.briefing, proximity.briefing.get, or contacts.digest.get, so an agent cannot tell these apart from the text alone.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives explicit trigger conditions: when the user asks what needs attention today, or at the start of a session where relationships matter, and asserts priority with 'call this first'. However, it offers no when-not guidance and does not name the competing briefing tools as alternatives, which matters given three other 'briefing/digest' siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.